The present invention relates to a bearing bushing for a journal bearing of a brake shaft of a drum brake; at one end, the bearing bushing is provided on the outside with a circumferential, annular grease recess for the introduction of grease; distributing channels branch off in the axial direction from this grease recess, and open into a hole; lubricating channels which extend in the opposite axial direction are disposed on the inside of the bearing bushing.
With one heretofore known bearing bushing which has already been used for the same application, the distributing channels which proceed from the grease recess are connected directly via holes with the lubricating channels which extend on the inside in the opposite direction, and which at the end of the bearing bushing open out and therefore have a free discharge. With this heretofore known bearing bushing, the grease distribution, and in conjunction therewith the formation of the lubricating film, are inadequate. This is primarily true because the lubricating channels discharge freely, and therefore no grease build-up can be produced when the intercommunicating system of the distributing and lubricating channels are filled. Furthermore, these heretofore known bearing bushings have the drawback that, because of their use in drum brakes of road vehicles, moisture, especially in the form of salt spray, can enter from the outside and promote corrosion.
It is an object of the present invention to provide a bearing bushing of simple construction which effects an improved distribution of grease, and which makes possible the formation of a closed lubricating film which is sealed relative to the penetration of moisture.